Multi-strand finishing block

ABSTRACT

A multi-strand finishing block finishes two or more daughter strands slit from a parent bar. Each strand is rolled by at least two pairs of rolls arranged in tandem with the rolls of each pair being at right angles to the rolls of the other pair. A common drive shaft is in driving relation with all the pairs of rolls.

The present invention is concerned with the production of bar stock,especially steel bar stock, and in particular the invention is concernedwith the finishing of daughter bars of reduced cross-section formed byslitting a parent bar longitudinally.

It is known to slit a parent bar into two (or more) daughter bars forsubsequent finishing treatment in separate finishing lines.

FIG. 1 of the accompanying drawings is a plan view of a prior art twinstrand finishing line. The parent bar 1 is moved in the direction of itslength, along a path as indicated by the arrow, through the last standof the intermediate mill. On exiting the last intermediate stand the barpasses through a slitter 2 which slices the parent bar in the directionof its length into two daughter bars 3, 3'. The daughter bars 3', 3 arealso referred to as strands. The daughter strands pass along separatefinishing lines 5 and 5' which include separate diverging guide tubes 4,4. Each finishing line also includes a crop shear 6, a side looper 7 anda multi-stand finishing block 8. As shown in FIG. 1, each finishingblock comprises three stands arranged in tandem and driven from a commondrive motor 9 through a gearbox 10. Each motor 9 is located outside ofthe corresponding finishing line 5.

Downstream of the finishing blocks 8 the reduced daughter strands arepassed through separate converging guide tubes 11, 11' and then continueside-by-side adjacent the original longitudinal path for furthertreatment. When it is desired to produce strands of larger cross-sectionthan that of the daughter strands, the parent bar may be routed directlyalong the longitudinal path between the finishing lines, bypassing thefinishing blocks. A conveyor, not shown, is provided for this purpose.

The prior art twin strand finishing line shown in FIG. 1, suffers thedisadvantage of requiring duplication of the drive for each of thefinishing blocks and because the drives are separate it is necessary tobe able to adjust the speed of one finishing block relative to the otherand to keep the relative speeds constant. An electronic control isusually required. The finishing blocks 8 have to be spaced apart topermit the parent bar to be passed between them when slitting is notrequired and the angles of divergence and convergence of the guide tubes4 and 11 are constrained to be small. This means that the overall lengthof the finishing line, from the slitter to where the daughter strandscome together again downstream of the guide tubes 11, is determined bythe separation of the finishing lines and the angle of divergence andconvergence of the guide tubes.

A reduction in the overall length of the finishing line means that thedimensions of the building which houses the finishing line can bereduced and this results in a saving in constructional costs.

Accordingly the present invention resides in a finishing block forrolling at least two strands of bar simultaneously, said block providingfor each of the strands two pairs of rolls arranged in tandem with therolls of one pair being at right angles to the rolls of the other paircharacterised in the provision of a shaft having an input end and anoutput end with each pair of rolls being in driving relation with theshaft and the input end of the shaft being connectable to a drive motoror to, and in line with, the output end of a corresponding shaft of asimilar finishing block.

In one embodiment of the invention, the strands of bar extend alongthree or four parallel paths spaced from and located around a furtherpath and the axis of the drive shaft is located on the further path.When there are four paths, two of the parallel paths may be at a higherlevel and two of the parallel paths at a lower level than the furtherpath.

By ensuring that a common drive is employed and particularly byarranging for the common drive to be between the parallel paths alongwhich the strands travel, the overall size of the multi-strand finishingline can be reduced as compared with the prior art. The problem ofsynchronising the speeds of each of the finishing lines is alsoalleviated because a mechanical common drive shaft is in drivingrelation with all the pairs of rolls. The common drive shaft isconnected by a transmission to each pair of rolls and the transmissionlength to each pair of rolls is kept equal so that the transmission isdynamically balanced. A motor, electric or hydraulic, is connected tothe drive shaft and two or more motors connected in series may be usedto drive the common drive shaft.

By bringing the finishing lines as close together as possible, guidingis made easier and the multi-strand finishing block can be made as shortas possible because the lengths of the diverging and converging guidetubes can be shortened.

The present invention allows a multi-strand finishing block to have twoor more strands finished simultaneously.

In order that the invention may be more readily understood it will nowbe described, by way of example only, with reference to the accompanyingdrawings in which:

FIG. 1 is a plan view of a prior art twin-strand finishing line,

FIG. 2 is a plan view of a twin-strand finishing line in accordance withthe invention,

FIG. 3 is a plan view of a twin strand finishing block in accordancewith the invention,

FIG. 4 is a partially sectioned plan view of part of the finishing blockshown in FIG. 3,

FIG. 5 is a partially sectioned elevation on the line AA of FIG. 4 and

FIG. 6 is a partially sectioned axial elevation of a four strandfinishing block viewed along its axis.

Comparing FIG. 2 with FIG. 1, it can be seen that the parent bar 1usually a steel bar is slit into two strands as it leaves the last standof the intermediate mill. The two daughter strands pass along separatefinishing lines 5, 5' which include respective guide tubes 4, 4'. Thefinishing block 12 comprises three finishing block units in tandem eachof which provides two pairs of rolls for each strand. The two pairs ofrolls provided by each unit for each strand have their axes mutually atright angles. All of the rolls of all three finishing block units are indriving relation with a common drive shaft 13 which is driven by a motor14. The axis of the drive shaft 13 is between and spaced from the twoparallel paths of the finishing lines. After the two strands are rolledsimultaneously in the finishing block 12, the two strands convergethrough guide tubes 11, 11' and continue side-by-side downstream forfurther treatment.

It can be seen from a comparison of FIGS. 1 and 2, that the finishingline employing the twin strand finishing block embodying the inventionis shorter and less wide than the prior art finishing line of FIG. 1. Ina particular installation, a finishing line having the form shown inFIG. 1 has a length of approximately 50 meters, and an installationincluding a finishing block in accordance with the present invention isapproximately 30 m long.

Referring to FIG. 3, two twin strand units 12A, 12B of a twin strandfinishing block are shown.

The first unit 12A comprises a pair of rolls 15V arranged with theiraxes substantially vertical. Downstream there is a pair of rolls 15Harranged with their axes substantially horizontal. One daughter strandpasses along the path 5 successively between the rolls 15V and 15H to bereduced in cross-section. Similarly, another daughter strand passesalong the path 5' successively between a pair of horizontal rolls 16Hand a pair of vertical rolls 16V. The two paths taken by the strands areon opposite sides of a further path 17 on which a drive shaft 18 lies.This drive shaft is in driving relation with all of the rolls 15V, 15H,16V and 16H. The drive shaft is connected to a motor 19 which has itslongitudinal axis along the further path. As shown in FIG. 3, two ormore motors arranged in series may be employed.

A second unit 12B is arranged downstream of first unit 12A and isidentical with unit 12A in that it provides a pair of horizontal rolls20H and a pair of vertical rolls 20V for each strand. The finishingblock units 12A, 12B are connected together mechanically on the furtherpath 17 so that all the rolls of the unit 12B are driven by the motor19. Although the rolls 15, 16 and 20 have been described as having theirroll axes vertical or horizontal, the axes need not be horizontal orvertical but the axes of each pair of rolls are mutually at right anglesto the preceding and succeeding pairs of rolls.

As shown in FIGS. 4 and 5, the common drive for all the rolls of thefirst unit 12A comprises an input drive shaft 18 lying below a pass line"P" of the parent bar. The input drive shaft 18 is coupled at itsdownstream end to the upstream end of an input drive shaft of the secondtwin strand unit 12B. It will be appreciated that any number of twinstrand units can be conveniently coupled together in series. Also, wornor failed twin strand units can be easily removed for maintenance andsubsequently replaced.

A left hand input bevel gear 21L and a right hand input bevel gear 21Rare mounted facing opposite each other on the input drive shaft 18. Theleft hand bevel gear 21L couples the input drive shaft 18 a mechanicaltransmission which is coupled to the pairs of rolls 16V and 16H on theleft hand side of the drive shaft. The right hand bevel gear 21R issimilarly coupled to a mechanical transmission for driving rolls 15H and15V on the right hand side of the drive shaft. The components of thetransmission on the right hand side are similar to those of thetransmission on the left hand side and so for the sake of concisenessonly the components of the transmission on the left hand side will bedescribed.

The left hand bevel gear 21L is meshed with an output bevel gear, i.e. atransmission bevel gear 22L which is mounted upon one end of a driveshaft 23L, extending at right angles away from the input drive shaft 18.The left drive shaft 23L may be inclined upwardly as shown in FIG. 5 andis supported in a pair of spaced bearings 24L. A first spur gear 25L ismounted on the drive shaft 23L between the pair of bearings 24L. A firstbevel gear assembly 26L is coupled to the end of the drive shaft 23L toturn the drive through ninety degrees in order to couple the drive shaftto a first drive shaft 27L which is inclined downwardly from the bevelgear assembly 26L to minimise the width of the twin strand finishingblock. The bottom end of the first drive shaft 27L is coupled with asecond drive shaft 28L by means of a second spur gear assembly wherebythe rolls 16V are coupled to the drive motor.

The first spur gear 25L is meshed with a third spur gear 29L which ismounted on a drive shaft, which, by means of a gear box 30L couples thehorizontal rolls 16H to the drive motor.

It will be noted that the two finishing lines, comprising the two rollstands and their transmission from the shaft 18 are similar except fortheir position.

By inclining the left and right drive shafts of the transmission in theway described space, is provided above the axis of the twin strandfinishing block along the pass line "P" to allow a parent bar to passdirectly through the twin strand finishing block avoiding the rolls 15and 16.

The basic concept of the present invention allows the twin-strandfinishing block structure to be readily extended to three, four or evenmore parallel strand finishing block structure each finishing line beingcoupled to the drive motor 19 by way of its input bevel gear 21 mountedon the input drive shaft 18 and a transmission bevel gear 22.

The second embodiment illustrates a four strand finishing block havingfour finishing lines disposed radially around a horizontal path providedby the input drive shaft 18. Two opposing input bevel gears 21 aremounted on the input drive shaft 18 in the same way as the firstembodiment. In FIG. 6 only the downstream input bevel gear 21 is shownbecause of the section. The transmission bevel gears 22 of two radiallyopposite finishing lines are meshed with the downstream input bevel gear21 to couple the upper right and the lower left finishing lines to thedrive shaft 18. The upper left and lower right twin roll finishing linesare similarly coupled to the downstream input bevel gear. Each finishingline is similar to the finishing line described in respect of the firstembodiment.

A similar drive, driven from a common drive source, can be provided fora three strand finishing block.

What is claimed is:
 1. A finishing line for rolling at least two standsof bar simultaneously and comprising for each of the strands amultiplicity of pairs of rolls arranged in tandem with the rolls of eachpair being at right angles of those of the or each pair adjacent to it,said pairs of rolls being provided by at least two similar finishingblocks arranged in tandem with each block providing for each strand twoof said pairs of rolls arranged mutually at right angles, each blockhaving a single drive shaft in driving relation with all the pairs ofrolls of the block and said drive shafts of said blocks being releasablyconnected in series to a common drive means.
 2. A finishing block asclaimed in claim 1 characterised in that the strands of bar extend alongseparate parallel paths (5, 5') spaced from a further path (17) and theaxis of the shaft (18) is located on said further path (17).
 3. Afinishing block as claimed in claim 2 in which there are four parallelpaths and two of said parallel paths are at a lower level than saidfurther path.